The Metropolitan police have launched an operation to crack down on crime ahead of the Notting Hill Carnival.
Police said they had issued 200 search warrants across London this week to "target and disrupt those intending to use the Notting Hill Carnival as a cover for committing crime or violence", with 55 arrests taking place.
Class A drugs and "many weapons", including machetes, a firearm, and ammunition, have been recovered as part as of the operation.
Superintendent Robyn Williams stressed, however, that given "well over 1 million people attend the Notting Hill Carnival every year, given these huge numbers, crime is low."
Separate figures published today reveal there is a significant spike in pickpocketing in the borough of Kensington and Chelsea when the carnival takes place.
In 2015 there were 250 pickpocketing thefts recorded by police – 1,567% higher than the 15 recorded in the seven days before the event.
The data, given to BuzzFeed News following a freedom of information request by the insurance company Policy Expert, shows the value of goods stolen at the carnival last year was £89,343, with the average item worth £357.
Mobile phones were the most commonly stolen item, closely followed by debit and credit cards.
In total, 153 mobile phones and 102 credit or debit cards were stolen during last year's carnival, as well as 56 wallets, 12 watches, 10 handbags, eight passports and visas, and two laptops.
Superintendent Williams added: "What we want is for those 1 million people to enjoy the event without worrying about the crime and violence that has been caused by the small minority in the past.
"With carnival being the largest event in London, it can present opportunities for those who are attending for reasons other than enjoying the festivities. It is only right that we take steps to deter and reduce crime at every opportunity.
"If you're coming to this year's event we want you to have a safe and enjoyable time. Please look after your belongings, and in particular keep an eye on your mobile phone. Almost half of those people who were victims of pickpockets last year had a mobile phone taken."
The carnival is a celebrated event in the London calendar, but has been beset with crime. Last year, police arrested more than 400 people – the highest number since 2008. Twenty-one officers were assaulted at the event last year, with one stabbed and one bitten. A teenager was also taken to hospital after being stabbed.
At the carnival in 2014 police officers arrested 95 people for offences including drugs, public disorder, assault, possession of offensive weapons, and theft. They also arrested 126 people in the run-up to the event.